The present disclosure relates generally to synchronizing a video source (e.g., a system on chip (SOC)) and display circuitry. More particularly, the disclosure relates to synchronizing the video source and display circuitry using a dynamic tearing effect (TE) signal.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
A wide variety of electronic devices include some form of electronic display. Such devices include cellular telephones, tablet computers, laptop computers, personal computers, televisions, headphones, Bluetooth® enabled watches, printers, and cameras, just to name a few. To display images, a video source of the electronic device provides a frame of image data to the electronic display, where the image data is stored in a memory device known as a “frame buffer.” The electronic display reads the image data out of the frame buffer and causes the image data to be represented on the display. At any time, the electronic display reads only one frame of image data from the frame buffer. That is, since one frame of image data may differ from the next, reading part of a first frame and part of a second frame onto the electronic display at the same time could produce what is known as a “tearing effect,” with part of the electronic display showing the first frame and part of the electronic display showing the second frame.
To avoid the tearing effect, the electronic display may emit a tearing effect (TE) signal in a pulse that indicates to the video source when the video source may provide the image data to the electronic display to be saved into the frame buffer. Specifically, the electronic display may emit the TE signal pulse at a time when the electronic display is not reading out of the frame buffer. In this way, only one frame of image data will be stored in the frame buffer during any readout of the image data by the display. This pulsed form of synchronization between the video source and the electronic display may rely on a static refresh rate, but this may preclude the use of a variable refresh rate.